Electric fuse.



A. J. SMITH.

ELECTRIC FUSE.

APPLICATION FILED JUNE 15,1909.

Patented June 14,1910.

have invented certain new and use der surrounding the interior parts 0 UNITED STATES PATENT OFFICE.

ANTHONY J. SMITH, OF NEW YORK, N. Y., ASSIGNOR OF ONE-THIRD TO WILLIAM J. SMITH, OF NEW YORK, N. Y.

ELECTRIC FUSE.

Specification of Letters Intent.

Patented June 14, 1910.

Application fled June 15, 1909. Serial No. 502,221.

To all whom it may concern:

Be it known that I, ANTHONY J. SMITH, a citizen of the United States of America, residing in New York, in the boron h of Manhattan, county and State of New ork,

ful Imrovements in Electric Fuses, of which the ollowing is a specification.

This invention relates to an improved electric fuse which can be readily repaired by the electric engineer of a station or other attendant whenever the fusible strip is burned out, so as to produce considerable economy in repairs and in the cost of new fuses; and for this purpose the invention consists of an electric fuse which comprises a fixed interior shell having an elongated opening, an exterior shell turnable thereon and provided with an opening registering with the opening of the fixed shell, caps attached to opposite ends of the fixed shell, holders for the fusible strip connected through the ca 5 with the conducting-wires, a strip of fusible metal supported by the holders, and a filling of non-conductingtpowthe fuse.

The invention consists further of certain details of construction which will be fully described hereinafter and finally pointed out in the claims.-

In the accompanying drawings, Figures 1 and 2 are front-elevations of my improved electric fuse, showing the same respectively in closed and opened position, Fig. 2 permitting the removal of a burned out and replacing of a new fusible strip, Fig.3 is a vertical transverse section on line 3, 3, Fig. 2, Fig. 4 is also a vertical transverse section taken on line 4, 4, Fig. 3, at a plane at right angles to the section shown in Fig. 3, Figs. 5, 6 and 7 are horizontal sections respectively on line 5, 5, Fig. 1, 6, 6, Fig. 2, and 7 7, 3, and Fig. 8 is a pers ective view of the astening device of one o the holders for the fusible strip.

Similar letters of reference indicate corresponding parts throughout the several figures.

Referring to the drawings, a represents the inner fixed shell of my improved electric fuse. The shell 0 is made of non-conducting material. It,is provided at one side with an elongated opening 0. Caps 0 are attached to the opposite ends of the inner shell (1, the

caps being made of brass or other suitable metal. Between the caps 0 is arranged on the fixed shell a turnable exterior shell a, which is also made of non-conducting material. It is'provided with an o ening 0 of the same size as the opening 0 o the shell 0, so that when the exterior shell is turned .on its 'axis both openings 0, 0 are made to coincide with each other. The conductors d for the current are passed through the caps 0 to the interior of the shell a, and are connected at their inner ends by intermediate fastening strips [1, with holders it that are attached to the fastening strips h by screws or rivets h The connecting strips h are attached at their opposite ends to the inner ends of the conductors (Z, as shown in Figs. 3 and 4. The holders h are preferably made of two yielding and inwardly-bent springclamps h. which are bent up from an upright main-plate h, from which latter is bent up at rlght angles to the plate h, a lug it that is connected by means of a screw or rivet h with the fastening stri 71. The inwardly-bent spring-clamps h o the holders 7:. permit the easy insertion of the thickened heads 6 of the strip 6 of fusible metal, the heads 6 being pressed inwardly between the spring-clamps until they abut against the main-plate ]t*. The caps 0 are connected with the opposite ends of the inner shell a by means of locking strips f, the tapering and outwardly bent ends of which are sprung into small holes f in the end of the inner shell and cap, as shown clearly in Fig. 4. The locking strips f hold the caps rigidly in position of the ends of the shell, without requiring exterior fastening screws or the like. The interior of the shell a is filled with a packing g of magnesia-powder that is carefully packed around the fusible strip, holders and connecting strips, as shown in Figs. 3 and 4, after which the exterior shell a is turned so as to place the openings 0, 0 out of register and produce thereby the tight and reliable closing of the shells.

In case the fusible strip burns out, the fuse can be readily replaced by turning the exterior shell until the opening in the same 00- incides with the opening in the interior shell, then' removing the pulverized ma esiapacking from the interior of the shel next removin the burned strip, and replacing a new fusible strip into the holders h. The powdered magnesia is then returned and carefully packed around the parts in the shells and around the fusible metal strip, after which the outer shell is turned around the interior shell so that the openings are placed out of register with each other. By this construction of the electric fuse, the attendants at the station can readily repair a fuse Without throwing the same away or returning the fuse for repairs to the shop. All that is necessary is to keep a supply of fusible strips on hand. By this arrangement not only a considerable saving in fuses is made, but also time saved in replacing the fusible strips burned out, by new strips, whereby loss or waste of fuses is avoided.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In an electric fuse, the combination of an inner cylindrical shell having a hole therein, caps at each end of the shell, conductors passing through said caps, a fuse connecting the inner ends of and an outer cylindrical shell turnable on said inner shell and held against longitudinal movement by the flanges of said caps and having a hole adapted to be moved in and out of register with the hole of said inner shell.

2. In an electric fuse, the combination of an inner shell having a closable opening, caps attached to opposite ends of the shell, fastening strips secured at their ends to said caps and Within the ends of said shell, and folded to form spaced portions, conductors said conductors, 1

passed through said caps and secured to and between said spaced portions, and a fuse connected at each end to said fastening strips respectively.

3. In an electric fuse, the combination of an inner shell having a closable opening, caps attached to the ends of said shell, fastening strips having their ends attached to the flanges of said caps and being bent to form a transverse middle portion and intermediate spaced parallel portions, conductors passing through said caps and secured to and betweensaid spaced portions, holders secured to said transverse portions, and a fuse connecting said holders.

4. In an electric fuse, the combination of an inner shell having a closable opening, capsattaclied to the ends of said shell, fastening strips having their ends attached to the flanges of said caps and being bent to form a transverse middle portion and intermediate spaced parallel portions, conductors passing through said caps and secured to and between said spaced portions, holders each having a bent-up strip connected to one of said transverse portions and having spaced spring-clamps, and a packing of non-conducting powder in said shell.

In testimony, that I claim the foregoing as my'invention, I have signed my name in presence of two subscribing witnesses.

ANTHONY J. SMITH. lVitnesses PAUL GOEPEL, FANNIE FISK. 

